This invention pertains to the field of control systems of physical events that are to be proportionally controlled by a user via a user interface. Examples of this capability would be for; manual control of a robotic arm, control of icon or sprite on a computer game graphics display and scale model railroad layouts to improve the control of whistle and other sound effect generation or function capabilities.
The following discussion summarizes the rapidly expanding art of model railroad control systems and shows how many diverse elements affect the reduction to practice of adding a proportional capability to a model railroad layout control system.
The era of prototype (full-size) steam-powered locomotives carrying significant railroad tonnages has passed, but nostalgic model railroaders enjoy the sounds of “live steam” on model railroad layouts. In addition to steam “chuff” sounds of moving steam locomotives, bell and steam whistle effects are particularly favored by modelers.
A steam powered locomotive whistle is very distinctive, and many new innovations in model railroad sound systems strive to provide realistic and controllable whistles on scale model railroad layouts. Examples of this would be modern DCC controlled sound decoders from Soundtraxx Inc. of Durango CO and ESU Electronics GmbH of Ulm Germany.
On non-digital or conventional analog DC controlled model railroads, the Pacific Fast Mail or PFM sound system has been very popular since the 1980's and creates very realistic sound images that are synchronized to the motion of the model locomotives, particularly narrow-gauge models. A favorite PFM sound effect is a “playable” or variable pitch steam whistle, which recreates the action of a prototype engineer varying the whistle steam valve to modulate the steam whistle pitch, harmonics and intensity. This provides a lot of realistic “character” to the operation of a model locomotive. The PFM system creates the playable whistle with a hand operable pivoting whistle pitch control lever on the control unit. In the rest position this whistle pitch control lever ensures that no whistle sound is generated. As the lever is actuated and its angle is changed the whistle sound effect is generated and is modified in pitch proportionally to the lever angle. Thus moving the lever up and down allows the generation of a controllable, continuously variable and playable whistle.
In the PFM design, the sounds created in this manner are conducted from the control unit via the layout rails to a speaker mounted in the locomotive, and optionally to speakers mounted around the layout. This arrangement permits a single high quality sound system for one train on the rails connected to a single control unit. Several other sound control units exist, for example units from Model Rectifier Corporation and Chicago International that employ slider controls to allow a modeler to create a playable whistle on a conventional DC model railroad layout.
To date the only variable pitch whistle effects that have been introduced into digitally controlled model railroads are within the Marklin GmbH 1-Guage sound units on layouts controlled by their Trinary square-wave digital control system. In this system a binary state accessory function control key associated with whistle control is depressed on the control unit, or throttle, that activates the whistle in the digital sound generator in the model locomotive, and is also used to indirectly control a variable whistle pitch. After the locomotive whistle is activated by the whistle function key depression, the whistle pitch begins to change in the digital sound generator in a manner controlled in proportion to the time the key is depressed. This provides a controllable whistle pitch with the standard Marklin binary function state control system components, but lacks the impression of continuously variable pitch that a lever or slider control creates. This Marklin control method, since it is a digital control system, has the desirable advantage that it permits the realistic operation of a multiplicity of whistle equipped digital locomotives in the same area of layout tracks.
Note that the prior art attempts some types of sound varying control by employing binary (on/off) or other inconvenient or unrealistic user interfaces. For example, Wolf in U.S. Pat. No. 6,457,681 teaches a “Doppler” sound simulation that may be initiated by the user, but this is limited by the fact that the Doppler pitch and amplitude changes of Wolf are (for a given train speed) predetermined for both up and down changes, and thus are less than realistic. This is not a true proportional effect under direct user control.
In this manner the prior art provides playable whistle effects or other modifiable sound, but with limitations in all the implementations.
Computer input devices have been developed to a fine art with examples such as Parsons in U.S. Pat. No. 5,286,089 and Ono et al. U.S. Pat. No. 5,555,004. All this work is aimed at providing force sensitive computer input pointing devices that are fully integrated as a device that is manufactured as a single assembly. These mechanisms are not designed as an adjunct or upgrade to add capabilities to an existing conventional key array structure. The implied or derived force measurement is used to provide X and Y position or a selection click or double-click as a user input, and is not localized to attaching extra sense capability to any single key in a key array.
An example of the use of this invention with a model railroad layout is the provision of proportional commands from a manual user input device (throttle) that communicates with a digital layout control system connected to a model railroad layout and ultimately to a decoder that makes use of these proportional commands to control sound generation or other features that can benefit from proportional commands.
The commanding of a desired train speed is specifically defined and stated as not being a proportional effect within the meaning of “proportional” used in this disclosure, since the speed of the trains have been commanded by control inputs since the first electric trains were produced over 100 years ago, and is a different effect or aspect than is described in this invention. Note that users and even specifications often interchange the terms locomotive and train. Typically a train comprises a locomotive and other rolling stock as a unit for railroad scheduling and routing. This specification may use either terms to be consistent with prior art, and by context it should be clear that a referral to “train” is to a locomotive with or without extra rolling stock, and that in many cases an internal decoder device is installed. Decoder devices may also be usefully employed for control in rolling stock other than powered locomotives and even connected to the rails in a stationary configuration.
Prior art such as Wolf, U.S. Pat. No. 6,457,681, is an example of a layout control system that allows control of model trains with sound and other capabilities that have some similarities to this invention. However, this technology taught by Wolf is not state of the art, and is surpassed with the configurations disclosed herein.
Wolf teaches a track control signal that “injects”, adds or modulates a controlling RF baseband direct sequence spread spectrum signal upon an AC (or DC) power signal. This is an architectural constraint to allow the use of a mixture of “conventional” or legacy trains (that are not modified to take advantage of increased control features) alongside newer digital trains. The conventional power signal that these “legacy” locomotives normally respond to is typically a transformer controlled variable-AC voltage that is detailed well by Severson in U.S. Pat. No. 4,914,431. The locomotives that can use this AC voltage to operate are typically 3-rail O-scale trains made by Lionel, Marx, K-Line, etc. This O-scale train market segment is often referred to as the “Toy Train” market as distinct from the “Scale model” railroad market where a 3-rail track is not considered to be visually prototypical.
By contrast, a large number of scale model railroaders in the US employ 2-rail DC controlled trains in HO and N scales, such as those made by Athearn, Kato and others. For this majority of modelers, the natural modern control choice (that still allows legacy train operation) is based on the well-known National Model Railroad Association (NMRA) standard for Digital Command Control (DCC). The NMRA open standard for DCC has been in wide use since the mid-1990's and uses a track drive signal that is a saturated-level digital bipolar square-wave waveform based on a packet technology, which is a distinctly different and superior technology to Wolf for this type of application.
Wolf is limited in the forms of modulation he can claim injected into a power signal, because of his citation of the 1980 Keith Gutierrez CTC-16 art that also injects a control modulation onto a power signal, in this case a modulation impressed onto DC power. In the 1990's Gutierrez subsequently upgraded the CTC-16 to CTC-2000 that employs a digital signal added to a DC power signal.
The large HO and N scale market segment cannot be addressed by the Wolf '681 art because the provision of the Analog Zero Stretching Method for NMRA DCC that allows legacy control of DC trains mixed with digital trains [detailed in section 13.3 of the book “Digitrax Big Book of DCC”—ISBN#0-9674830-0-X, published 1999, and entered herein as additional reference for layout control prior art] is not addressed or taught by Wolf as within the scope of his art, and additionally, is not compatible with legacy operation of 3-rail AC O-scale trains.
Impressing or injecting an RF spread spectrum control signal with variable DC power for control of a DC conventional train, does not allow for a stationary DC conventional train to create sound, light effects and even smoke, as would be needed to provide a realistic model when stopped a at train station or yard. DC 2-rail modelers demand this capability, which Wolf does not teach or provide for.
The DCC signal is superior to Wolf's signal because it encodes commands in the full track amplitude waveform excursions, and is easily filtered and protected from any practical system noise and track configuration disturbances and permits a mixture of unmodified (legacy) and digital trains to operate on the same tracks. DCC has been used successfully for control of trains in all model scales, from Z-scale to Guage-1.
Wolf's injection of a modulated RF signal on a power signal invites problem of signal propagation and signal strength on the rails, even if a modicum of noise rejection is conferred by direct sequence spread spectrum technology. Neil Besoughloff in the book “Command Control for Toy Trains” page 93, (ISBN# 0-89778-523-1) details these problems the Wolf technology has on real layouts. The RF signal strength problem is reportedly so bad on some layouts that users must add lamps or other “transmission line impedance termination” patches to try and ensure stable and reliable operation.
By contrast, on DCC layouts if there is sufficient signal to allow a train to move, a decoder (designed by one skilled in the art of DCC and train control technology) is guaranteed to remain under positive control. Note that, unlike DCC, Wolf's controlling modulated RF signal without an additional power signal is inoperative and not of sufficient power to move the trains. If this RF signal were increased to be sufficiently energetic to operate a train (in range of about 12 to 100 watts), because of the antenna effects of the track wiring and rails, it would then have to be licensed by the FCC as an intentional RF radiator or transmitter and would then have; health, shock and burn hazard consequences on open rails, and would likely be impossibly restricted in allowable carrier or emission frequencies.
A DCC or any other known digital bipolar square-wave type of digital control signal such as; Marklin Trinary, Trix, FMZ and Zimo, is indivisible from the layout energization means, and is not simply a RF control signal riding “piggy-back” on a power signal or source.
The direct sequence spread spectrum modulation RF control signal taught by Wolf is significantly more complex to synchronize, correlate and decode within the recipient decoder device, when compared to DCC. This means a higher cost, power consumption and larger size for a decoder when comparing equivalent levels of implementation technologies, which is contrary to the expectations and wishes of the market and consumers.
Another limitation of the Wolf '681 art is the method by which system components are interconnected and the system is expanded.
Prior art taught by Ireland in U.S. Pat. No. 6,275,739, incorporated herein by reference, shows the benefit of all system elements being interconnected in discipline via a bi-directional multiple-access data network. This Ireland prior art specifically teaches a throttle device that is connected bi-directionally to a layout control system. This throttle may also be a remote or un-tethered throttle, and gain access by a radio/RF or infra-red communication link that supports this bi-directional multiple-access data network capability. [item 16 FIGS. 1 and 2, and lines 37–40 col 1 and lines 39–41 of col 3 of Ireland '739]. Of great importance for a system using a bi-directional multiple-access data network is that the data flows are not mediated centrally by a single device such as a Command Station, Track Interface Unit or equivalent central control means. With this method, all elements or devices on the network enjoy the freedom of being involved in any type of data transfer, in any direction, by simply following; the network access rules, grammar and control capability incorporated in that device. The ease of expandability and interconnect taught in U.S. Pat. No. 6,275,739 is thus both a prior art and a distinct advance over the art of Wolf '681.
Dunsmuir, in U.S. Pat. No. 5,638,522, and Katzer, in U.S. Pat. No. 6,065,406 also teach the addition of computer(s) to allow automated operations by detection and controlling the layout and expanding the way multiple interfaces may be added to model railroad layouts, and are additional prior art distinct from U.S. Pat. No. 6,275,739. Dunsmuir shows a hierarchical design that employs a Token ring network interconnection for most control elements, but that is based on the supremacy of a single master/slave PC with a complex graphical user interface to animate most layout capabilities. Master/slave architecture compromises system growth choices and scalability.
All these PC control applications, including for example “Timetable” capability in the Winlok 2.1 software by Digitoys Systems Inc. and the “flagman” in the RailRoad and Co. software, show examples that allow the user to pre-configure or record a complex sequence of layout actions and train commands, that can be modified by layout detection, to expand layout control. These permit, but are not limited to; the automation of routes (a sequence of turnout activations), the stopping of trains on signal/occupancy state, interlocking the safe movement of trains, the display of locations of trains and the announcement or triggering of a sound file when a train has reached a location. These capabilities are well documented in the “Digitrax Big Book of DCC”, including section 11 which teaches a large PUTRA automated DCC training layout in Kuala Lumpur, Malaysia that was in operation before 1999. The Digitrax LocoNet used in the PUTRA simulator model layout allows the convenience of multiple PC's running the Winlok 2.1 software to be connected simultaneously to provide multiple terminals and also diagnostic capability.
A bi-directional or “Transponding” data connection to a decoder device taught by Ireland in U.S. Pat. No. 6,220,552, incorporated herein by reference, teaches and allows the real time dynamic tracking of locations of multiple trains and decoder devices on the layout, and the interrogation of data that is decoder device state information such as; measured distance traveled, control input states (e.g. if a load is situated on a boxcar or a pantograph is down, a turnout is closed, etc.), train speed, motor load/current draw and speed compensation amount, and any other manufacturer specific and configurable data or program information such as NMRA Configuration Variable (CV) settings and status reports, error conditions or downloaded sound fragments that may be employed by the decoder devices to generate sounds around the layout. A decoder device may be mobile or stationary within the layout control system and can be connected via an expansion device, signal repeater or booster. The detection system is then configured to receive the response signal from the decoder device, and this in combination with encoded track commands addressed to the decoder device, clearly forms a bi-directional data link, and flow.
Ames, in U.S. Pat. No. 6,539,292, claims the ability for a system to modify its control based on the detected location of a decoder device. The Ames' '292 specification clearly shows [lines 34–37 col 4] that the Ireland '552 art meets his description and can be described as equivalent to his “bi-directional communication”.
Ames states incorrectly that Ireland '552“ . . . can only acknowledge a specific command sent to it and cannot initiate a communication on its own.” [lines 21–26 col 3]. This is contradicted by the specification of Ireland '552, and claim 7, that clearly is for a device that can respond when not interrogated by its own address, and is hence not limited by the rate it is explicitly addressed. A number of other clearly false statements and conclusions are stated by Ames. For example, Ames misstates the Ireland 552 prior art by stating: “The Digitrax approach, like the Zimo approach, both suffer from the command refresh rate.” [lines 30–31 col 3 of Ames '292].
Ireland '552 explicitly teaches [lines 19–23 of col 21] that the decoder responses (that clearly meet Ames' definition of bi-directional capability) have the benefit of being “ . . . not limited by the rate commands are sent to any single address.” This Ireland prior art teaches a device that can initiate a response without being constrained by the system.
Unfortunately the Ames' specification, by redefining or labeling a decoder response to a command as “bi-directional” and stating many false limitations of the Ireland '552 prior art, misleads the examiner in a matter that is fundamentally at the heart of Ames' claims for novelty over the prior art of bi-directional data communication and control.
Wolf '681 fails to anticipate or teach the ability of his invention to identify the address and then to use this to track train position as it moves around the layout. This tracking (e.g. ‘Transponding’) is definitively a form of bi-directional data feedback and acknowledgement. Wolf '681 only mentions contact switches or IR position sensors for location detection, and does not teach expanded detection of occupancy or position feedback by utilizing the conducted track voltage or current waveforms, or how this expanded detection and position information then may be employed to automate or advance the control capability of the layout by any connected control element. Marklin and others have employed as prior art; contact switches, IR or laser reflective/transmissive sensors, optical Bar codes, magnetic detectors and RF identification to provide detection for control and display purposes. The use of visual pattern recognition to identify and detect rolling stock has also been discussed, and color-coded swatches have been tried by the prototype railroads for visual detection and control.
The Ireland '552 prior art teaches and anticipates a wide diversity of data exchange and bi-directional capability with decoders connected to the layout, including the ability to detect and alert train derailment or removal from the layout and system so the system can respond and modify its behavior. Section 10.0 of “The Big Book of DCC” clearly teaches many examples of the layout control system adapting its behavior to train location feedback, and even shows an example of the system making a decision to run the train around a reverse loop if needed after recognizing the bi-directional data feedback of a transponding device address.
At the 1993 NMRA National Train Show and Convention in Valley Forge Pa., the MiniTrix control system (from the Trix company of Germany) was demonstrated with miniature ceramic board decoders in HO and N scale that employed a Digital square-wave track control signal and a back-emf motor speed control with fine speed resolution and speed/load compensation. At this time, and up to 1998, several other companies such as Marklin, Zimo, Lenz and Arnold also demonstrated digital decoders with back-emf speed/load compensation. The Umelec Company of Switzerland also demonstrated a version of speed/load compensating digital decoder with an optical sensor on the motor flywheel to provide speed/load compensation, as an alternate to sensing motor speed by back-emf. All these prior art decoders employed a control strategy such as the well known Proportional Integral Derivative (PID) servo control loop method. This allows the decoder to compensate for the slowing down or speeding up of the motor in response to a change in load (i.e. the “droop” or speed/load sensitivity), and thus tend to hold any constant speed commanded by a user. Severson in U.S. Pat. No. 5,448,142 teaches some of the control possibilities for employing the back-emf detected from a motor on a model train, such as laboring of sounds when an increased motor load is detected, etc.
From August 1999, Digitrax Inc. was shipping the DZ121, DH140U and HAG501 decoders that had back-emf load compensation called “Scalable Speed Stabilization” (denoted as ‘SS’ capability in August 1999 Digitrax catalog, p38/39), and having 128-step resolution. This allowed scalability, such that the user could adjust the “droop” or speed/load compensation characteristics on the fly. This allowed the Intensity or droop CV (CV57) of the back-emf PID type loop to be dynamically programmed in operation, such that the droop amount (or speed/load curve sensitivity) could be changed to suit the model and power characteristics needed. For example, a minimum droop CV57 of zero means that the back-emf load compensation is turned off and the model behaves like an unmodified DC motor locomotive, and this is similar to the performance of most US prototype diesel locomotives. Conversely maximum droop CV57 setting ensures the most constant train speed, irrespective of the train length and load and whether the train is on a up, down or flat grade. In between settings of droop CV57 allow a proportionate compensation effect. The CV57 droop adjustment is a new and separate coefficient within the speed control algorithm distinct from the three Proportional, Integral and Differential coefficients of a classic PID loop and conveniently interacts with all 3 PID terms separately.
Most early US diesel prototypes, with the exception of the SD9, did not have load compensation from the wheel speed to the prime-mover engine and generator. By contrast many European prototype diesel locomotives employ a drive scheme that speed/load compensates to ensure a more constant track speed to allow for busy track and train schedules. So, with a simple adjustment of CV57 in real time the user can choose the most realistic droop for the model to use at that time.
For US modelers with large consists of multiple engines there is another advantage to modifying the droop CV. Here it is desirable to lower the droop CV value in the locomotives, otherwise any differences in speed or compensation accuracy between the locomotive decoders will generate large coupler forces between the locomotives (the “pushy-pusher” effect) and can contribute to derailments. This is such a useful feature that there is an additional consist droop CV in Digitrax back-emf decoders available to automatically invoke this change when the decoder is consisted.
With the scalable 128 step resolution back-emf decoder capability, Digitrax users intrinsically interpret the numeric digital speed display in DT100 (or like throttles or computer based throttles) as showing the train speed in convenient units, typically as miles per hour. The value of speed curve slope CVs can also be easily modified to show the speed in kilometers per hour, as discussed in the “Digitrax Big Book of DCC”.
Wolf, in U.S. Pat. No. 6,619,594, fails to be aware of or acknowledge this widely known body of prior art in the industry that directly and publicly contradicts the novelty of his claims.
Novosel et al, in U.S. Pat. No. 5,855,004 teach the benefit of digitally generated sounds in locomotive decoders using an NMRA DCC control signal. This work was actually anticipated and demonstrated in the DSD2408 DCC sound decoder shown publicly by SoundTraxx at the Amherst Train show, 14 months before being added as new matter to the Novosel specification.
In early 1999 ESU GmbH demonstrated a DCC compatible sound decoder that allowed the user to download to the decoder in the locomotive customizable sound fragments and a control sequencing scheme from; a recorded computer wave sound (.wav, etc) file, CD or the Internet via the track. Information can also be uploaded from the decoder and sent off via the Internet for Customer Service use. The operating state changes of the ESU decoder allowed the user to custom configure these looped sound fragments for steam chuffs (or diesel prime mover) when the decoder changes from accelerating under load, running steadily and decelerating with lighter load. For diesels, the prime mover pitch and volume are modulated based on throttle demand, and unique startup and shutdown sounds are also part of the sound-sequencing scheme. Note that the ESU decoder allows the decoder setup to be modified or downloaded into flash or EEPROM memory even when the train is running on the layout. The multi-format Uhlenbrock “Intellibox” was introduced in 1998 which allowed the DCC, Marklin Trinary and Trix formats to be interspersed on the track. This unit also allows the operating software to be downloaded and updated via an Internet connection to the Uhlenbrock website.
SoundTraxx Inc., ESU Electronics, Novosel '004 and Wolf '594 prior art only teach integrated motor, function and sound decoders in one combined module.
In 2003 the Dietz Company of Germany offered the NMRA a specification for a Serial User Standard Interface (SUSI) method that allows a sound generator to be hooked to a decoder with a synchronous data link employing a clock wire, data wire, a power wire for DC power supplied by decoder, and ground wire that connects via a 4 pin 1 mm pitch connector. However, this interface does not implement a proportional command interface and is not configured to allow the sound generator to decode commands directly from the track. Additionally the clock and data wires are dedicated to the synchronous data link and are not operable as separate general-purpose function control lines.
Severson '142 teaches the modification of sound based on back-emf load. Wolf U.S. Pat. No. 6,619,594 discusses storage of different chuff sounds based on load, but does not claim this capability. Novosel U.S. Pat. No. 5,855,004 claims storage of sounds at different workloads. All these prior arts fail to address the reality that the steam chuffs undergo a continuous change when trainloads vary and not, say for example, a series of 3 or more pre-recorded sound examples.
For several years the NMRA DCC Working group has been informally contemplating a SoundTraxx Inc. request for an Analog Control instruction for the track that is usable for a part of a NMRA DCC compatible version of this invention, but this has not been taught in a complete functional form and reduced to practice.
Since the mid 1990's the LocoLink products from Lake Oswego OR have shown the ability of RF remote throttles to directly control a decoder in a locomotive, without the need for external track control signals. The Digitrax and Zimo systems, before 1998, demonstrate remote throttles that can operate DCC type control systems by Radio Frequency and/or Infra Red signals. The RF systems to date have been of a fixed or a limited number of discrete frequencies, and this poses limits to the number of throttles and layouts that can operate at e.g. a Train Show. The Digitrax RF data link employs a 900 MHz band FM modulation scheme that uses Time Division Multiplex messaging methods.
Wolf '681 employs an RF (intentionally radiated) radio link (as opposed to his additional RF spread-spectrum signal conducted via rails to the trains) between the remote control and TIU unit. Here Wolf uses a simple 900 MHz band OOK keying (100% AM modulation) method to create this radio link, but fails to teach the need for, or benefits of, other radio link architectures that overcome the problems both this OOK modulation scheme and RF data link design have with interference, multiple proximate users, or any channel management issues.
The improvements over the prior art used in this invention, and in combination, allow a greater level of realism and capability for model railroad layouts with a increased flexibility and lower cost.